Resin-molded package with cavity structure

ABSTRACT

A package includes: a substrate having a ridged peripheral portion and a center portion defined by and lower in level than the ridged peripheral portion. A semiconductor chip is mounted on the center portion. A plurality of lead is electrically coupled to the semiconductor chip and penetrates the substrate outwardly from the center portion. The package also includes a cap defining a cavity space which accommodates the semiconductor chip. The cap has a cap bonding face bonded with a substrate bonding face of the ridged peripheral portion. The cap bonding face and the substrate bonding face are higher in level than the center portion.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a division of application Ser. No. 10/144,313, filedon May 7, 2002, now U.S. Pat. No. 7,004,325, the entire contents ofwhich are hereby incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a resin-molded package, and moreparticularly to a resin-molded package including a resin substrate and aresin-cap defining a cavity structure and having a reduced leadinductance for an ultra-high frequency semiconductor device.

2. Description of the Related Art

It has been known that a ceramic package with a cavity structure issuitable for packaging an ultra-high frequency semiconductor devicebecause the ceramic package reduces a dielectric constant and aparasitic capacitance of the semiconductor device. The ceramic packageis disadvantageous in its high cost and expensive.

On the other hand, a resin-molded package with a cavity structure hasbeen attracted due to its lower cost and inexpensive. The resin-moldedpackage includes a resin substrate, on which a semiconductor chip ismounted, and a resin cap which defines a cavity in cooperation with thesemiconductor chip, so that the semiconductor chip is accommodated inthe cavity space. The resin cap is adhered to the resin substrate.

For the ultra-high frequency semiconductor device, it is preferable toreduce an inductance thereof for suppressing a high frequency lossthereof. To reduce the inductance, it is preferable to make short asmany as possible the length of the leads. In this viewpoint, a lead-lesstype cavity structured package is preferable.

Japanese patent No. 2600689 and Japanese patent No. 3127584 disclose thelead-less type cavity structured packages. The lead-less type cavitystructured package includes a resin substrate, a semiconductor chipmounted on the resin substrate, leads penetrating the resin substratefrom an upper surface to a bottom level of the substrate and also beingelectrically coupled through metal wirings to the semiconductor chip,and a cap adhered to the resin substrate to define the cavity spacewhich accommodates the semiconductor chip. This lead-less type cavitystructured package is advantageous in less inductance of the leads thanthe leaded package with long leads which project outwardly from sides ofthe package and further which are bent downwardly outside the package.

The above lead-less type cavity structured packages disclosed in theabove two Japanese patents have the following common disadvantages.

First, the above package is mounted on a circuit board through a solderbonding process which provides an electrical connection between theleads and conductive patterns of the circuit board. The solder bondingprocess is carried out by placing the package into a solder vessel whichis filled with a flux. It is possible that a part of the flux entersinto the cavity. If the resin substrate has a flat and horizontal topsurface which bounds with the cap, then this flat and horizontal topsurface makes it easy to allow the flux to enter into the cavity. If theflax enters into the cavity and further is made into contact with atleast a part of the semiconductor chip, then this may provide a failureto the electrical characteristic and performance of the packagedsemiconductor device.

It is necessary to prevent or avoid the entry of flux into the cavity.In order to prevent or avoid the entry of flux into the cavity, it iseffective that the top flat and horizontal surface of the resinsubstrate has a high level from the bottom level of the substrate so asto ensure a sufficient height of the top flat and horizontal surface ofthe resin substrate from a top surface of the flux. This means that theheight or thickness of the resin substrate is large. This resinsubstrate structure needs long leads which penetrate from the uppersurface thereof to the bottom surface or level thereof. The long leadshave a large inductance which makes it difficult to suppress theundesirable high frequency loss of the ultra-high frequencysemiconductor device.

Second, the flat and horizontal top surface of the resin substrate isbounded with the cap. In order to create a sufficient cavity space forthe semiconductor chip with the bonding wires, it is necessary that thecap has a sufficiently large height. This results in a large totalthickness or height of the package.

Third, the cap is aligned to the resin substrate by using an automaticassembling machine. The flat and horizontal top surface of the resinsubstrate allows displacement or miss-alignment of the cap to the resinsubstrate. The package size is small, for example, a diameter of about 2millimeters and a thickness of about 0.5 millimeters. The displacementor miss-alignment makes defective the external dimension of the package.The defective external dimension of the package makes it easy todisconnect the metal wirings.

In the above circumstances, the development of a novel package with acavity structure free from the above problems is desirable.

SUMMARY OF THE INVENTION

Accordingly, it is an object of the present invention to provide a novelpackage with a cavity structure free from the above problems.

It is a further object of the present invention to provide a novelpackage with a cavity structure having a reduced lead inductance.

It is a still further object of the present invention to provide a novelpackage with a cavity structure having a reduced total height.

It is yet a further object of the present invention to provide a novelpackage with a cavity structure, which prevents an entry of flux intothe cavity.

It is further more object of the present invention to provide a novelpackage with a cavity structure, which has a self-alignment featurebetween a cap and a substrate.

The present invention provides a package includes: a substrate having aridged peripheral portion and a center portion defined by and lower inlevel than the ridged peripheral portion. A semiconductor chip ismounted on the center portion. A plurality of lead is electricallycoupled to the semiconductor chip and penetrates the substrate outwardlyfrom the center portion. The package also includes a cap defining acavity space which accommodates the semiconductor chip. The cap has acap bonding face bonded with a substrate bonding face of the ridgedperipheral portion. The cap bonding face and the substrate bonding faceare higher in level than the center portion.

The upper surface of the center portion, on which the semiconductor chipis mounted, is lower in level than a top of the ridged peripheralportion. This structural feature may advantageously prevent anundesirable entry of flux into the cavity. Namely, the ridged peripheralportion serves as a flux barrier wall which surrounds the centerportion, on which the semiconductor chip is mounted, wherein the fluxbarrier wall is effective to prevent the entry of flux into the cavity.This may cause no failure to the electrical characteristic andperformance of the packaged semiconductor device.

The above structural feature may also advantageously allow an effectivereduction in thickness of the center portion so that a distance betweenupper and bottom surfaces of the center portion is reduced, therebyallowing a reduction in minimum length of the plurality of lead forpenetrating the substrate outwardly from the center portion. Thereduction in length of the plurality of lead decreases the inductancethereof. The decrease in the inductance of the plurality of leads makesit easy to suppress the undesirable high frequency loss of the highfrequency semiconductor device.

The above structural feature may further provide an effective reductionin height of the cap with ensuring the sufficient cavity space whichaccommodates the semiconductor chip. This allows an effective reductionin the total height of the package.

Further, the cap bonding face and the substrate bonding face are engagedwith each other, and each of the cap bonding face, and the substratebonding face includes at least a non-horizontal face for causing aself-alignment function for self-aligning the cap to the substrate. Thisself-alignment function allows an automatic assembling process by usingan automatic assembling machine without any excess highhanding-accuracy. The above self-alignment function makes non-defectivethe external dimension of the package. The non-defective externaldimension of the package makes the metal wirings free from anyundesirable disconnection. The above self-alignment function also allowsthe mass production and improves the yield of the final product.

The above and other objects, features and advantages of the presentinvention will be apparent from the following descriptions.

BRIEF DESCRIPTION OF THE DRAWINGS

Preferred embodiments according to the present invention will bedescribed in detail with reference to the accompanying drawings.

FIG. 1 is a cross sectional elevation view illustrative of an internalstructure of a novel package with a cavity structure in a firstembodiment in accordance with the present invention.

FIG. 2 is a plan view illustrative of a novel package with a cavitystructure shown in FIG. 1.

FIG. 3 is a cross sectional elevation view illustrative of an internalstructure of a novel package with a cavity structure in a secondembodiment in accordance with the present invention.

FIG. 4 is a cross sectional elevation view illustrative of an internalstructure of a novel package with a cavity structure in a thirdembodiment in accordance with the present invention.

FIG. 5 is a cross sectional elevation view illustrative of an internalstructure of a novel package with a cavity structure in a fourthembodiment in accordance with the present invention.

FIG. 6 is a cross sectional elevation view illustrative of an internalstructure of a novel package with a cavity structure in a fifthembodiment in accordance with the present invention.

FIG. 7 is a cross sectional elevation view illustrative of an internalstructure of a novel package with a cavity structure in a sixthembodiment in accordance with the present invention.

FIG. 8 is a cross sectional elevation view illustrative of an internalstructure of a novel package with a cavity structure in a seventhembodiment in accordance with the present invention.

FIG. 9 is a cross sectional elevation view illustrative of an internalstructure of a novel package with a cavity structure in an eighthembodiment in accordance with the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

A first aspect of the present invention is a package including: asubstrate having a ridged peripheral portion and a center portiondefined by the ridged peripheral portion, and an upper surface of thecenter portion being lower in level than a top of the ridged peripheralportion; a semiconductor chip mounted on the upper surface of the centerportion; a plurality of lead being electrically coupled to thesemiconductor chip and the plurality of lead penetrating the substrateoutwardly from the center portion; and a cap defining a cavity spacewhich accommodates the semiconductor chip, and the cap having a capbonding face bonded with a substrate bonding face of the ridgedperipheral portion, and the cap bonding face and the substrate bondingface being higher in level than the upper surface of the center portion.

The upper surface of the center portion, on which the semiconductor chipis mounted, is lower in level than the top of the ridged peripheralportion. This structural feature may advantageously prevent anundesirable entry of flux into the cavity. Namely, the ridged peripheralportion serves as a flux barrier wall which surrounds the upper surfaceof the center portion, on which the semiconductor chip is mounted,wherein the flux barrier wall is effective to prevent the entry of fluxinto the cavity. This may cause no failure to the electricalcharacteristic and performance of the packaged semiconductor device.

The above structural feature may also advantageously allow an effectivereduction in thickness of the center portion so that a distance betweenupper and bottom surfaces of the center portion is reduced, therebyallowing a reduction in minimum length of the plurality of lead forpenetrating the substrate outwardly from the center portion. Thereduction in length of the plurality of lead decreases the inductancethereof. The decrease in the inductance of the plurality of leads makesit easy to suppress the undesirable high frequency loss of the highfrequency semiconductor device.

The above structural feature may further provide an effective reductionin height of the cap with ensuring the sufficient cavity space whichaccommodates the semiconductor chip. This allows an effective reductionin the total height of the package.

Further, the cap bonding face and the substrate bonding face are engagedwith each other, and each of the cap bonding face, and the substratebonding face includes at least a non-horizontal face for causing aself-alignment function for self-aligning the cap to the substrate. Thisself-alignment function allows an automatic assembling process by usingan automatic assembling machine without any excess highhanding-accuracy. The above self-alignment function makes non-defectivethe external dimension of the package. The non-defective externaldimension of the package makes the metal wirings free from anyundesirable disconnection. The above self-alignment function also allowsthe mass production and improves the yield of the final product.

It is preferable that each of the cap bonding face and the substratebonding face comprises an inwardly sloped-down plane surface whichannularly extends. This structure provides the self-alignment functionfor self-aligning the cap to the substrate. If the cap is miss-alignedto the substrate, then the cap bonding face and the substrate bondingface are not engaged with each other, but also the inwardly sloped-downplane surfaces guide the cap to be just-aligned to the substrate,whereby the cap bonding face and the substrate bonding face becomeengaged with each other. This self-alignment function allows theautomatic assembling process by using the automatic assembling machinewithout any excess high handing-accuracy. The above self-alignmentfunction makes non-defective the external dimension of the package. Thenon-defective external dimension of the package makes the metal wiringsfree from any undesirable disconnection. The above self-alignmentfunction also allows the mass production and improves the yield of thefinal product.

Further, the inwardly sloped-down plane surfaces provides the maximumheight of the flux barrier wall at the outside thereof This makes itdifficult that the flux reaches an interface between the cap bondingface and the substrate bonding face, thereby preventing the entry of theflux into the cavity through the interface between the cap bonding faceand the substrate bonding face.

It is also preferable that each of the cap bonding face and thesubstrate bonding face comprises a combination of a sloped plane surfaceand a horizontal and flat surface which annularly extend. This structureprovides the self-alignment function for self-aligning the cap to thesubstrate. If the cap is miss-aligned to the substrate, then the capbonding face and the substrate bonding face are not engaged with eachother, but also the inwardly sloped-down plane surfaces guide the cap tobe just-aligned to the substrate, whereby the cap bonding face and thesubstrate bonding face become engaged with each other. Thisself-alignment function allows the automatic assembling process by usingthe automatic assembling machine without any excess highhanding-accuracy. The above self-alignment function makes non-defectivethe external dimension of the package. The non-defective externaldimension of the package makes the metal wirings free from anyundesirable disconnection. The above self-alignment function also allowsthe mass production and improves the yield of the final product.

It is also preferable that each of the cap bonding face and thesubstrate bonding face comprises an outwardly sloped-down plane surfacewhich annularly extends. This structure provides the self-alignmentfunction for self-aligning the cap to the substrate. If the cap ismiss-aligned to the substrate, then the cap bonding face and thesubstrate bonding face are not engaged with each other, but also theoutwardly sloped-down plane surfaces guide the cap to be just-aligned tothe substrate, whereby the cap bonding face and the substrate bondingface become engaged with each other. This self-alignment function allowsthe automatic assembling process by using the automatic assemblingmachine without any excess high handing-accuracy. The aboveself-alignment function makes non-defective the external dimension ofthe package. The non-defective external dimension of the package makesthe metal wirings free from any undesirable disconnection. The aboveself-alignment function also allows the mass production and improves theyield of the final product.

Further, it is preferable that the inside periphery of the outwardlysloped-down plane surface of the substrate is positioned inside of theinside periphery of the outwardly sloped-down plane surface of the cap,so that the outwardly sloped-down plane surface of the substrate has aninside extending region which further extends in the inward and upwarddirection from the inside periphery of the outwardly sloped-down planesurface of the cap. The outwardly sloped-down plane surfaces providesthe maximum height of the flux barrier wall at the inside thereof. Theinside extending region of the outwardly sloped-down plane surface ofthe substrate makes it difficult that a part of the flux crimes up inthe inward direction along the inside extending region, assuming thatthe part of the flux passes through the interface between the substratebonding face and the cap bonding face due to capillary phenomenon. Thisensures to prevent the flux from entering into the cavity.

It is also preferable that first one of the cap bonding face and thesubstrate bonding face includes at least a convexity which annularlyextends and second one thereof comprises a concavity which annularlyextends and engaged with the convexity. This structure with thecombination of the engaging convexity and concavity provides theself-alignment function for self-aligning the cap to the substrate. Ifthe cap is miss-aligned to the substrate, then the cap bonding face andthe substrate bonding face are not engaged with each other, but also thecombination of the engaging convexity and concavity guides the cap to bejust-aligned to the substrate, whereby the cap bonding face and thesubstrate bonding face become engaged with each other. Thisself-alignment function allows the automatic assembling process by usingthe automatic assembling machine without any excess highhanding-accuracy. The above self-alignment function makes non-defectivethe external dimension of the package. The non-defective externaldimension of the package makes the metal wirings free from anyundesirable disconnection. The above self-alignment function also allowsthe mass production and improves the yield of the final product.

Further, the combination of the engaging convexity and concavitycontributes to capture a part of the flux wherein, assuming that thepart of the flux passes through the interface between the substratebonding face and the cap bonding face due to capillary phenomenon. Thisensures to prevent the flux from entering into the cavity. It isparticularly preferable that the cap bonding face comprises theconvexity and the substrate bonding face comprises the concavity, andthe substrate bonding face is wider width than the cap bonding face, sothat the concavity is larger in size than the convexity. This furtherstructural feature makes it easy to capture the part of the flux intothe concavity. This ensures to prevent the flux from entering into thecavity.

For example, it is possible that the convexity comprises a rounded ridgewhich annularly extends, and the concavity comprises a rounded groovewhich annularly extends and is engaged with the rounded ridge. In thiscase, it is possible that the cap bonding face comprises the roundedridge and the substrate bonding face comprises the rounded groove.Alternatively, it is possible that the cap bonding face comprises therounded groove and the substrate bonding face comprises the roundedridge.

For example, it is possible that the convexity comprises a tapered ridgewhich annularly extends, and the concavity comprises a tapered groovewhich annularly extends and is engaged with the tapered ridge. In thiscase, it is possible that the cap bonding face comprises the taperedridge and the substrate bonding face comprises the tapered groove.Alternatively, it is possible that the cap bonding face comprises thetapered groove and the substrate bonding face comprises the taperedridge. The tapered ridge may optionally comprise a V-shaped ridge, andthe tapered groove may optionally comprise a V-shaped groove.

This structure with the combination of the engaging ridge and grooveprovides the self-alignment function for self-aligning the cap to thesubstrate. If the cap is miss-aligned to the substrate, then the capbonding face and the substrate bonding face are not engaged with eachother, but also the combination of the engaging ridge and groove guidesthe cap to be just-aligned to the substrate, whereby the cap bondingface and the substrate bonding face become engaged with each other. Thisself-alignment function allows the automatic assembling process by usingthe automatic assembling machine without any excess highhanding-accuracy. The above self-alignment function makes non-defectivethe external dimension of the package. The non-defective externaldimension of the package makes the metal wirings free from anyundesirable disconnection. The above self-alignment function also allowsthe mass production and improves the yield of the final product.

Further, the combination of the engaging ridge and groove contributes tocapture a part of the flux wherein, assuming that the part of the fluxpasses through the interface between the substrate bonding face and thecap bonding face due to capillary phenomenon. This ensures to preventthe flux from entering into the groove. It is particularly preferablethat the cap bonding face comprises the ridge and the substrate bondingface comprises the groove, and the substrate bonding face is wider widththan the cap bonding face, so that the groove is larger in size than theridge. This further structural feature makes it easy to capture the partof the flux into the groove. This ensures to prevent the flux fromentering into the cavity.

Further, alternatively, the tapered ridge may optionally comprise atrapezoid-shaped ridge, and the tapered groove may optionally comprise atrapezoid-shaped groove. The combination of the trapezoid-shaped ridgeand groove makes it easy to apply an adhesive agent onto at least one offlat portions of the trapezoid-shaped ridge and groove.

It is preferable that the plurality of lead extends sloped from theupper surface of the center portion to a bottom periphery of thesubstrate. The slope-extension of the plurality of lead may alsoadvantageously allow a further reduction in the length of the pluralityof lead for penetrating the substrate outwardly from the center portion.The further reduction in length of the plurality of lead furtherdecreases the inductance thereof. The further decrease in the inductanceof the plurality of leads makes it easy to further suppress theundesirable high frequency loss of the high frequency semiconductordevice.

It is preferable that the cap comprises a flat body and a peripheralportion which has the cap bonding face. The structural feature mayprovide a further reduction in height of the cap with ensuring thesufficient cavity space which accommodates the semiconductor chip. Thisallows a further reduction in the total height of the package.

A second aspect of the present invention is a package including asubstrate having a peripheral portion and a center hollow portiondefined by the peripheral portion, and an upper surface of the centerhollow portion being lower in level than a top of the peripheralportion; a semiconductor chip mounted on the upper surface of the centerhollow portion; a plurality of lead being electrically coupled to thesemiconductor chip and the plurality of lead penetrating the substrateand extending sloped from the upper surface of the center hollow portionto a bottom periphery of the substrate; and a cap defining a cavityspace which accommodates the semiconductor chip, and the cap comprisinga flat body and a peripheral portion which has a cap bonding face bondedwith a substrate bonding face of the peripheral portion, and the capbonding face and the substrate bonding face being higher in level thanthe upper surface of the center hollow portion, the cap bonding face andthe substrate bonding face being engaged with each other, and each ofthe cap bonding face and the substrate bonding face includes at least anon-horizontal face.

The upper surface of the center hollow portion, on which thesemiconductor chip is mounted, is lower in level a top of than theperipheral portion. This structural feature may advantageously preventan undesirable entry of flux into the cavity. Namely, the peripheralportion serves as a flux barrier wall which surrounds the center hollowportion, on which the semiconductor chip is mounted, wherein the fluxbarrier wall is effective to prevent the entry of flux into the cavity.This may cause no failure to the electrical characteristic andperformance of the packaged semiconductor device.

The above structural feature may also advantageously allow an effectivereduction in thickness of the center portion so that a distance betweenupper and bottom surfaces of the center portion is reduced, therebyallowing a reduction in minimum length of the plurality of lead forpenetrating the substrate outwardly from the center portion. Thereduction in length of the plurality of lead decreases the inductancethereof. The decrease in the inductance of the plurality of leads makesit easy to suppress the undesirable high frequency loss of the highfrequency semiconductor device.

The above structural feature may further provide an effective reductionin height of the cap with ensuring the sufficient cavity space whichaccommodates the semiconductor chip. This allows an effective reductionin the total height of the package.

Further, the cap bonding face and the substrate bonding face are engagedwith each other, and each of the cap bonding face, and the substratebonding face includes at least a non-horizontal face for causing aself-alignment function for self-aligning the cap to the substrate. Thisself-alignment function allows an automatic assembling process by usingan automatic assembling machine without any excess highhanding-accuracy. The above self-alignment function makes non-defectivethe external dimension of the package. The non-defective externaldimension of the package makes the metal wirings free from anyundesirable disconnection. The above self-alignment function also allowsthe mass production and improves the yield of the final product.

It is preferable that each of the cap bonding face and the substratebonding face comprises an inwardly sloped-down plane surface whichannularly extends. This structure provides the self-alignment functionfor self-aligning the cap to the substrate. If the cap is miss-alignedto the substrate, then the cap bonding face and the substrate bondingface are not engaged with each other, but also the inwardly sloped-downplane surfaces guide the cap to be just-aligned to the substrate,whereby the cap bonding face and the substrate bonding face becomeengaged with each other. This self-alignment function allows theautomatic assembling process by using the automatic assembling machinewithout any excess high handing-accuracy. The above self-alignmentfunction makes non-defective the external dimension of the package. Thenon-defective external dimension of the package makes the metal wiringsfree from any undesirable disconnection. The above self-alignmentfunction also allows the mass production and improves the yield of thefinal product.

Further, the inwardly sloped-down plane surfaces provides the maximumheight of the flux barrier wall at the outside thereof. This makes itdifficult that the flux reaches an interface between the cap bondingface and the substrate bonding face, thereby preventing the entry of theflux into the cavity through the interface between the cap bonding faceand the substrate bonding face.

It is also preferable that each of the cap bonding face and thesubstrate bonding face comprises a combination of a sloped plane surfaceand a horizontal and flat surface which annularly extend. This structureprovides the self-alignment function for self-aligning the cap to thesubstrate. If the cap is miss-aligned to the substrate, then the capbonding face and the substrate bonding face are not engaged with eachother, but also the inwardly sloped-down plane surfaces guide the cap tobe just-aligned to the substrate, whereby the cap bonding face and thesubstrate bonding face become engaged with each other. Thisself-alignment function allows the automatic assembling process by usingthe automatic assembling machine without any excess highhanding-accuracy. The above self-alignment function makes non-defectivethe external dimension of the package. The non-defective externaldimension of the package makes the metal wirings free from anyundesirable disconnection. The above self-alignment function also allowsthe mass production and improves the yield of the final product.

It is also preferable that each of the cap bonding face and thesubstrate bonding face comprises an outwardly sloped-down plane surfacewhich annularly extends. This structure provides the self-alignmentfunction for self-aligning the cap to the substrate. If the cap ismiss-aligned to the substrate, then the cap bonding face and thesubstrate bonding face are not engaged with each other, but also theoutwardly sloped-down plane surfaces guide the cap to be just-aligned tothe substrate, whereby the cap bonding face and the substrate bondingface become engaged with each other. This self-alignment function allowsthe automatic assembling process by using the automatic assemblingmachine without any excess high handing-accuracy. The aboveself-alignment function makes non-defective the external dimension ofthe package. The non-defective external dimension of the package makesthe metal wirings free from any undesirable disconnection. The aboveself-alignment function also allows the mass production and improves theyield of the final product.

Further, it is preferable that the inside periphery of the outwardlysloped-down plane surface of the substrate is positioned inside of theinside periphery of the outwardly sloped-down plane surface of the cap,so that the outwardly sloped-down plane surface of the substrate has aninside extending region which further extends in the inward and upwarddirection from the inside periphery of the outwardly sloped-down planesurface of the cap. The outwardly sloped-down plane surfaces providesthe maximum height of the flux barrier wall at the inside thereof. Theinside extending region of the outwardly sloped-down plane surface ofthe substrate makes it difficult that a part of the flux crimes up inthe inward direction along the inside extending region, assuming thatthe part of the flux passes through the interface between the substratebonding face and the cap bonding face due to capillary phenomenon. Thisensures to prevent the flux from entering into the cavity.

It is also preferable that first one of the cap bonding face and thesubstrate bonding face includes at least a convexity which annularlyextends and second one thereof comprises a concavity which annularlyextends and engaged with the convexity. This structure with thecombination of the engaging convexity and concavity provides theself-alignment function for self-aligning the cap to the substrate. Ifthe cap is miss-aligned to the substrate, then the cap bonding face andthe substrate bonding face are not engaged with each other, but also thecombination of the engaging convexity and concavity guides the cap to bejust-aligned to the substrate, whereby the cap bonding face and thesubstrate bonding face become engaged with each other. Thisself-alignment function allows the automatic assembling process by usingthe automatic assembling machine without any excess highhanding-accuracy. The above self-alignment function makes non-defectivethe external dimension of the package. The non-defective externaldimension of the package makes the metal wirings free from anyundesirable disconnection. The above self-alignment function also allowsthe mass production and improves the yield of the final product.

Further, the combination of the engaging convexity and concavitycontributes to capture a part of the flux wherein, assuming that thepart of the flux passes through the interface between the substratebonding face and the cap bonding face due to capillary phenomenon. Thisensures to prevent the flux from entering into the cavity. It isparticularly preferable that the cap bonding face comprises theconvexity and the substrate bonding face comprises the concavity, andthe substrate bonding face is wider width than the cap bonding face, sothat the concavity is larger in size than the convexity. This furtherstructural feature makes it easy to capture the part of the flux intothe concavity. This ensures to prevent the flux from entering into thecavity.

For example, it is possible that the convexity comprises a rounded ridgewhich annularly extends, and the concavity comprises a rounded groovewhich annularly extends and is engaged with the rounded ridge. In thiscase, it is possible that the cap bonding face comprises the roundedridge and the substrate bonding face comprises the rounded groove.Alternatively, it is possible that the cap bonding face comprises therounded groove and the substrate bonding face comprises the roundedridge.

For example, it is possible that the convexity comprises a tapered,ridge which annularly extends, and the concavity comprises a taperedgroove which annularly extends and is engaged with the tapered ridge. Inthis case, it is possible that the cap bonding face comprises thetapered ridge and the substrate bonding face comprises the taperedgroove. Alternatively, it is possible that the cap bonding facecomprises the tapered groove and the substrate bonding face comprisesthe tapered ridge. The tapered ridge may optionally comprise a V-shapedridge, and the tapered groove may optionally comprise a V-shaped groove.

This structure with the combination of the engaging ridge and grooveprovides the self-alignment function for self-aligning the cap to thesubstrate. If the cap is miss-aligned to the substrate, then the capbonding face and the substrate bonding face are not engaged with eachother, but also the combination of the engaging ridge and groove guidesthe cap to be just-aligned to the substrate, whereby the cap bondingface and the substrate bonding face become engaged with each other. Thisself-alignment function allows the automatic assembling process by usingthe automatic assembling machine without any excess highhanding-accuracy. The above self-alignment function makes non-defectivethe external dimension of the package. The non-defective externaldimension of the package makes the metal wirings free from anyundesirable disconnection. The above self-alignment function also allowsthe mass production and improves the yield of the final product.

Further, the combination of the engaging ridge and groove contributes tocapture a part of the flux wherein, assuming that the part of the fluxpasses through the interface between the substrate bonding face and thecap bonding face due to capillary phenomenon. This ensures to preventthe flux from entering into the groove. It is particularly preferablethat the cap bonding face comprises the ridge and the substrate bondingface comprises the groove, and the substrate bonding face is wider widththan the cap bonding face, so that the groove is larger in size than theridge. This further structural feature makes it easy to capture the partof the flux into the groove. This ensures to prevent the flux fromentering into the cavity.

Further, alternatively, the tapered ridge may optionally comprise atrapezoid-shaped ridge, and the tapered groove may optionally comprise atrapezoid-shaped groove. The combination of the trapezoid-shaped ridgeand groove makes it easy to apply an adhesive agent onto at least one offlat portions of the trapezoid-shaped ridge and groove.

First Embodiment

A first embodiment according to the present invention will be describedin detail with reference to the drawings. FIG. 1 is a cross sectionalelevation view illustrative of an internal structure of a novel packagewith a cavity structure in a first embodiment in accordance with thepresent invention. FIG. 2 is a plan view illustrative of a novel packagewith a cavity structure shown in FIG. 1.

A package 10 with a cavity structure includes a resin substrate 16, asemiconductor chip 18, and a cap 20. The resin substrate 16 furtherincludes a die pad 12 and a set of four leads 14. The resin substrate 16comprises a thickness-reduced center hollow portion 21 and a ridgedperipheral portion 22. The ridged peripheral portion 22 extendsannularly surrounding the periphery of the thickness-reduced centerhollow portion 21. An upper surface of the thickness-reduced centerhollow portion 21 is lower in level than the top of the ridgedperipheral portion 22. The ridged peripheral portion 22 serves as abarrier wall to flux for keeping the thickness-reduced center hollowportion 21 from the flux.

The die pad 12 is selectively provided in the thickness-reduced centerhollow portion 21. An upper surface of the die pad 12 has substantiallythe same level as an upper surface of the thickness-reduced centerhollow portion 21. The semiconductor chip 18 is mounted on the die pad12. The die pad 12 is positioned at a center of the resin substrate 16in a plan view. The die pad 12 is molded and united within thethickness-reduced center hollow portion 21.

In the plan view, the four leads 14 extend radially and outwardly fromaround the die pad 12 in four directions respectively. In the crosssectional view, each of the four leads 14 penetrates the resin substrate16 from the upper surface of the thickness-reduced center hollow portion21 to a bottom periphery of the resin substrate 16, and further projectsoutwardly from the bottom periphery. The each lead 14 comprises a highlevel inside portion, an intermediate sloped portion, and a low leveloutside portion.

The high level inside portion lies along the upper surface of thethickness-reduced center hollow portion 21. The high level insideportion has an upper-side exposed surface 30 which is exposed from theupper surface of the thickness-reduced center hollow portion 21. Theupper-side exposed surface 30 is electrically connected through a metalwiring to the semiconductor chip 18. The low level outside portion liesalong the bottom surface of the resin substrate 16 and is positionedoutside of the high level inside portion. The low level outside portionhas a lower-side exposed surface 32 which is exposed from the bottom ofthe resin substrate 16. The intermediate sloped portion is graduallysloped-down outwardly for providing a smooth connection between the highlevel inside portion and the low level outside portion. The each lead 14is molded and united within the resin substrate 16.

The ridged peripheral portion 22 extends annularly surrounding theperiphery of the thickness-reduced center hollow portion 21. The ridgedperipheral portion 22 includes an inside wall, an outside wall oppositeto the inside wall as well as a flat top face and an inwardlysloped-down face. The inwardly sloped-down face is bounded between theinside wall and the flat top face. The inwardly sloped-down face extendsoutside the inside wall and inside the flat top face. The flat top faceis bounded between the inwardly sloped-down face and the outside wall.The flat top face extends outside the inwardly sloped-down face andinside the outside wall. The inwardly sloped-down face has a circularband shape in the plan view. The inwardly sloped-down face has a uniformslope angle. In the geometrical viewpoint, the three dimensional shapeof the inwardly sloped-down face corresponds to a part of a conicalinner face, namely an inner face of a short truncated cone. The inwardlysloped-down face provides a substrate bonding face 28 for bonding withthe cap 20.

The cap 20 is bonded or adhered to the substrate bonding face 28comprising the inwardly sloped-down face of the ridged peripheralportion 22 of the resin substrate 16, whereby in co-operation with theresin substrate 16, the cap 20 defines a cavity 24 which accommodatesthe semiconductor chip 18. The cavity also contributes to reduce theparasitic capacitance. The cap 20 comprises a disk-shaped body 23 and aridged peripheral portion 25 which extends annularly surrounding aperiphery of the disk-shaped body 23. The disk-shaped body 23 isgenerally flat and relatively thin. The ridged peripheral portion 25 isridged downwardly and toward the resin substrate 16.

The ridged peripheral portion 25 includes an inside wall, an outsidewall opposite to the inside wall as well as an inwardly sloped-downface, provided that the cap 20 is bonded to the resin substrate 16 andthe inner wall is faced down. The inwardly sloped-down face is boundedbetween the inside and outside walls. The inwardly sloped-down faceextends outside the inside wall and inside the outside wall. Theinwardly sloped-down face has a circular band shape in the bottom view.In the geometrical viewpoint, the three dimensional shape of theinwardly sloped-down face corresponds to a part of a conical outer face,namely an outer face of a short truncated cone.

The inwardly sloped-down face of the cap 20 provides a cap bonding face26 which is adjusted with and engaged with the substrate bonding face 28of the resin substrate 16. The cap bonding face 26 has a uniform slopeangle which is identical with the uniform slop angle of the abovesubstrate bonding face 28, so that the cap bonding face 26 is tightlycontact and engaged with the substrate bonding face 28. As wellillustrated, the cap bonding face 26 may optionally be little narrowerin width than the substrate bonding face 28.

The cap bonding face 26 extends inside the flat top face of the ridgedperipheral portion 22 of the resin substrate 16. The inside periphery ofthe cap bonding face 26 extends outside the inside periphery of thesubstrate bonding face 28. The bonding interface between the cap bondingface 26 and the substrate bonding face 28 extends downwardly from thetop level of the resin substrate 16. This may contribute to reduce thetotal height or thickness of the package 10.

The above package 10 provides the following advantages.

The thickness-reduced center hollow portion 21 contributes to form thecavity 24 which accommodates the semiconductor chip 18, whilst the resinsubstrate 16 and the cap 20 are relatively reduced in height orthickness, and thus the total height or thickness of the package isreduced.

The upper surface of the thickness-reduced center hollow portion 21, onwhich the semiconductor chip 18 is mounted, is lower in level than thetop of the ridged peripheral portion 22 of the resin substrate 16. Thisstructural feature may advantageously prevent an undesirable entry offlux into the cavity 24. Namely, the ridged peripheral portion 22 servesas a barrier wall to flux which surrounds the thickness-reduced centerhollow portion 21, on which the semiconductor chip 18 is mounted. Theflux barrier wall of the ridged peripheral portion 22 is effective toprevent the entry of flux into the cavity 24. This may cause no failureto the electrical characteristic and performance of the packagedsemiconductor device.

Further, the inwardly sloped-down planes of the cap bonding face 26 andthe substrate bonding face 28 provide the maximum height of the fluxbarrier wall of the ridged peripheral portion 22 at the outside thereof.This makes it difficult that the flux reaches an interface between thecap bonding face 26 and the substrate bonding face 28, therebypreventing the entry of the flux into the cavity 24 through theinterface between the cap bonding face 26 and the substrate bonding face28.

The above structural feature may also advantageously allow an effectivereduction in thickness of the thickness-reduced center hollow portion 21so that a distance between upper and bottom surfaces of thethickness-reduced center hollow portion 21 is reduced, thereby allowinga reduction in the length of the leads 14 which extends from the uppersurface of the thickness-reduced center hollow portion 21 to the bottomperiphery of the resin substrate 16. The reduction in length of theleads 14 decreases the inductance thereof. The decrease in theinductance of the leads 14 makes it easy to suppress the undesirablehigh frequency loss of the high frequency semiconductor device.

Further, the each lead 14 includes the intermediate sloped portion. Theslope-extension may also advantageously allow a further reduction in thelength of the leads 14 for penetrating the resin substrate 16. Thefurther reduction in length of the leads 14 further decreases theinductance thereof. The further decrease in the inductance of the leads14 makes it easy to further suppress the undesirable high frequency lossof the high frequency semiconductor device.

The above structural feature may further provide an effective reductionin height of the cap 20 with ensuring the sufficient space of the cavity24 which accommodates the semiconductor chip 18. This allows aneffective reduction in the total height of the package.

Further, the cap bonding face 26 and the substrate bonding face 28 areengaged tightly with each other, and each of the cap bonding face 26,and the substrate bonding face 28 comprises the sloped face or thenon-horizontal face, which causes a self-alignment function forself-aligning the cap 20 to the resin substrate 16 due to a self-weightof the cap 20. This self-alignment function allows a desirable automaticassembling process by using an automatic assembling machine without anyexcess high handing-accuracy. The above self-alignment function makesnon-defective the external dimension of the package 10. Thenon-defective external dimension of the package 10 makes the metalwirings free from any undesirable disconnection. The aboveself-alignment function also allows the mass production and improves theyield of the final product.

In addition, the cap bonding face 26 extends inside the flat top face ofthe ridged peripheral portion 22 of the resin substrate 16. The insideperiphery of the cap bonding face 26 extends outside the insideperiphery of the substrate bonding face 28. The bonding interfacebetween the cap bonding face 26 and the substrate bonding face 28extends downwardly from the top level of the resin substrate 16. Thismay contribute to reduce the total height or thickness of the package10.

Second Embodiment

A second embodiment according to the present invention will be describedin detail with reference to the drawings. FIG. 3 is a cross sectionalelevation view illustrative of an internal structure of a novel packagewith a cavity structure in a second embodiment in accordance with thepresent invention. The package of this second embodiment is differentfrom the package of the first embodiment in the engaging substrate andcap bonding faces.

A package 40 with a cavity structure includes a resin substrate 42, asemiconductor chip 18, and a cap 44. The resin substrate 42 furtherincludes a die pad 12 and a set of four leads 14. The resin substrate 42comprises a thickness-reduced center hollow portion 43 and a ridgedperipheral portion 45. The ridged peripheral portion 45 extendsannularly surrounding the periphery of the thickness-reduced centerhollow portion 43. An upper surface of the thickness-reduced centerhollow portion 43 is lower in level than the top of the ridgedperipheral portion 45. The ridged peripheral portion 45 serves as abarrier wall to flux for keeping the thickness-reduced center hollowportion 43 from the flux.

The ridged peripheral portion 45 extends annularly surrounding theperiphery of the thickness-reduced center hollow portion 43. The ridgedperipheral portion 45 includes an inside wall, an outside wall oppositeto the inside wall as well as a flat top face, an inwardly sloped-downface and a flat terrace. The flat terrace is bounded between theinwardly sloped-down face and the inside wall. The flat terrace extendsoutside the inside wall and inside the inwardly sloped-down face. Theflat terrace is higher in level than the upper surface of thethickness-reduced center hollow portion 43, but lower in level than theflat top face.

The inwardly sloped-down face is -bounded between the flat terrace andthe flat top face. The inwardly sloped-down face extends outside theflat terrace and inside the flat top face. The flat top face is boundedbetween the inwardly sloped-down face and the outside wall. The flat topface extends outside the inwardly sloped-down face and inside theoutside wall. The flat terrace has a circular band shape in the planview, and no slope angle in cross sectional view. The inwardlysloped-down face has a circular band shape in the plan view. Theinwardly sloped-down face has a uniform slope angle. In the geometricalviewpoint, the three dimensional shape of the inwardly sloped-down facecorresponds to a part of a conical inner face, namely an inner face of ashort truncated cone. The inwardly sloped-down face provides a firstsubstrate bonding face 46 for bonding with the cap 44. The flat terracealso provides a second substrate bonding face 48 for bonding with thecap 44. The combination of the first and second substrate bonding faces46 and 48 provides the united substrate bonding face.

The cap 44 is bonded or adhered to the first and second substratebonding faces 46 and 48 respectively comprising the inwardly sloped-downface and the flat terrace of the ridged peripheral portion 45 of theresin substrate 42, whereby in co-operation with the resin substrate 42,the cap 44 defines a cavity 24 which accommodates the semiconductor chip18. The cavity also contributes to reduce the parasitic capacitance. Thecap 44 comprises a disk-shaped body 47 and a ridged peripheral portion49 which extends annularly surrounding a periphery of the disk-shapedbody 47. The disk-shaped body 47 is generally flat and relatively thin.The ridged peripheral portion 49 is ridged downwardly and toward theresin substrate 42.

The ridged peripheral portion 49 includes an inside wall, an outsidewall opposite to the inside wall as well as a flat bottom face and aninwardly sloped-down face, provided that the cap 44 is bonded to theresin substrate 42 and the inner wall is faced down. The flat bottomface is bounded between the inside wall and the inwardly sloped-downface. The flat bottom face extends outside the inside wall and insidethe inwardly sloped-down face. The flat bottom face has a circular bandshape in the bottom view. The inwardly sloped-down face is boundedbetween the flat bottom face and the outside wall. The inwardlysloped-down face extends outside the flat bottom face and inside theoutside wall. The inwardly sloped-down face has a circular band shape inthe bottom view. In the geometrical viewpoint, the three dimensionalshape of the inwardly sloped-down face corresponds to a part of aconical outer face, namely an outer face of a short truncated cone.

The inwardly sloped-down face of the cap 44 provides a first cap bondingface 50 which is adjusted with and engaged with the first substratebonding face 46 of the resin substrate 42. The flat bottom face of thecap 44 provides a second cap bonding face 52 which is adjusted with andengaged with the second substrate bonding face 48 of the resin substrate42. The first cap bonding face 50 has a uniform slope angle which isidentical with the uniform slop angle of the above first substratebonding face 46, so that the first cap bonding face 50 is tightlycontact and engaged with the first substrate bonding face 46. The secondcap bonding face 52 has no slope angle which is identical with the abovesecond substrate bonding face 48, so that the second cap bonding face 52is tightly contact and engaged with the second substrate bonding face48. As well illustrated, the second cap bonding face 52 may optionallybe little narrower in width than the second substrate bonding face 48.

The above package 40 provides the following advantages.

Similarly to the first embodiment, the thickness-reduced center hollowportion 43 contributes to form the cavity 24 which accommodates thesemiconductor chip 18, whilst the resin substrate 42 and the cap 44 arerelatively reduced in height or thickness, and thus the total height orthickness of the package is reduced.

Similarly also to the first embodiment, the upper surface of thethickness-reduced center hollow portion 43, on which the semiconductorchip 18 is mounted, is lower in level than the top of the ridgedperipheral portion 45 of the resin substrate 42. This structural featuremay advantageously prevent an undesirable entry of flux into the cavity24. Namely, the ridged peripheral portion 45 serves as a barrier wall toflux which surrounds the thickness-reduced center hollow portion 43, onwhich the semiconductor chip 18 is mounted. The flux barrier wall of theridged peripheral portion 45 is effective to prevent the entry of fluxinto the cavity 24. This may cause no failure to the electricalcharacteristic and performance of the packaged semiconductor device.

Similarly also to the first embodiment, the inwardly sloped-down planesof the first cap bonding face 50 and the first substrate bonding face 46provide the maximum height of the flux barrier wall of the ridgedperipheral portion 45 at the outside thereof. This makes it difficultthat the flux reaches an interface between the first cap bonding face 50and the first substrate bonding face 46, thereby preventing the entry ofthe flux into the cavity 24 through the interface between the first capbonding face 50 and the first substrate bonding face 46.

Similarly also to the first embodiment, the above structural feature mayalso advantageously allow an effective reduction in thickness of thethickness-reduced center hollow portion 43 so that a distance betweenupper and bottom surfaces of the thickness-reduced center hollow portion43 is reduced, thereby allowing a reduction in the length of the leads14 which extends from the upper surface of the thickness-reduced centerhollow portion 43 to the bottom periphery of the resin substrate 42. Thereduction in length of the leads 14 decreases the inductance thereof.The decrease in the inductance of the leads 14 makes it easy to suppressthe undesirable high frequency loss of the high frequency semiconductordevice.

The above structural feature may further provide an effective reductionin height of the cap 44 with ensuring the sufficient space of the cavity24 which accommodates the semiconductor chip 18. This allows aneffective reduction in the total height of the package.

Further, the first cap bonding face 50 and the first substrate bondingface 46 are engaged tightly with each other, and each of the cap bondingface 50, and the first substrate bonding face 46 comprises the slopedface or the non-horizontal face, which causes a self-alignment functionfor self-aligning the cap 44 to the resin substrate 42 due to aself-weight of the cap 44. This self-alignment function allows adesirable automatic assembling process by using an automatic assemblingmachine without any excess high handing-accuracy. The aboveself-alignment function makes non-defective the external dimension ofthe package 40. The non-defective external dimension of the package 40makes the metal wirings free from any undesirable disconnection. Theabove self-alignment function also allows the mass production andimproves the yield of the final product.

In addition, the second cap bonding face 52 and the second substratebonding face 48 are engaged tightly with each other, and each of thesecond cap bonding face 52 and the second substrate bonding face 48comprises the flat face or the horizontal face which makes it easy toapply an adhesive agent onto at least one of the second cap bonding face52 and the second substrate bonding face 48 for bonding the cap 44 tothe resin substrate 42. This may contribute to improve the productivityof the package 40.

Third Embodiment

A third embodiment according to the present invention will be describedin detail with reference to the drawings. FIG. 4 is a cross sectionalelevation view illustrative of an internal structure of a novel packagewith a cavity structure in a third embodiment in accordance with thepresent invention. The package of this third embodiment is differentfrom the package of the first embodiment in the cap and substratebonding faces.

A package 60 with a cavity structure includes a resin substrate 62, asemiconductor chip 18, and a cap 64. The resin substrate 62 furtherincludes a die pad 12 and a set of four leads 14. The resin substrate 62comprises a thickness-reduced center hollow portion 63 and a ridgedperipheral portion 65. The ridged peripheral portion 65 extendsannularly surrounding the periphery of the thickness-reduced centerhollow portion 63. An upper surface of the thickness-reduced centerhollow portion 63 is lower in level than the top of the ridgedperipheral portion 65. The ridged peripheral portion 65 serves as abarrier wall to flux for keeping the thickness-reduced center hollowportion 63 from the flux.

The ridged peripheral portion 65 extends annularly surrounding theperiphery of the thickness-reduced center hollow portion 63. The ridgedperipheral portion 65 includes an inside wall, an outside wall oppositeto the inside wall as well as an outwardly sloped-down face. Theoutwardly sloped-down face is bounded between the inside and outsidewalls. The outwardly sloped-down face extends outside the inside walland inside the outside wall. The outwardly sloped-down face has acircular band shape in the plan view. The outwardly sloped-down face hasa uniform slope angle. In the geometrical viewpoint, the threedimensional shape of the outwardly sloped-down face corresponds to apart of a conical outer face, namely an outer face of a short truncatedcone. The outwardly sloped-down face provides a substrate bonding face66 for bonding with the cap 64.

The cap 64 is bonded or adhered to the substrate bonding face 66comprising the outwardly sloped-down face of the ridged peripheralportion 65 of the resin substrate 62, whereby in co-operation with theresin substrate 62, the cap 64 defines a cavity 24 which accommodatesthe semiconductor chip 18. The cavity also contributes to reduce theparasitic capacitance. The cap 64 comprises a disk-shaped body 67 and aridged peripheral portion 69 which extends annularly surrounding aperiphery of the disk-shaped body 67. The disk-shaped body 67 isgenerally flat and relatively thin. The ridged peripheral portion 69 isridged downwardly and toward the resin substrate 62.

The ridged peripheral portion 69 includes an inside wall, an outsidewall opposite to the inside wall as well as an outwardly sloped-downface, provided that the cap 64 is bonded to the resin substrate 62 andthe inner wall is faced down. The outwardly sloped-down face is boundedbetween the inside and outside walls. The outwardly sloped-down faceextends outside the inside wall and inside the outside wall. Theoutwardly sloped-down face has a circular band shape in the bottom view.In the geometrical viewpoint, the three dimensional shape of theoutwardly sloped-down face corresponds to a part of a conical innerface, namely an inner face of a short truncated cone.

The outwardly sloped-down face of the cap 64 provides a cap bonding face68 which is adjusted with and engaged with the substrate bonding face 66of the resin substrate 62. The cap bonding face 68 has a uniform slopeangle which is identical with the uniform slop angle of the abovesubstrate bonding face 66, so that the cap bonding face 68 is tightlycontact and engaged with the substrate bonding face 66.

As well illustrated, the cap bonding face 68 may optionally be narrowerin width than the substrate bonding face 66. Namely, the outsideperiphery of the cap bonding face 68 extends inside the outsideperiphery of the substrate bonding face 66, whilst the inside peripheryof the cap bonding face 68 extends outside the inside periphery of thesubstrate bonding face 66.

The above package 60 provides the following advantages.

The thickness-reduced center hollow portion 63 contributes to form thecavity 24 which accommodates the semiconductor chip 18, whilst the resinsubstrate 62 and the cap 64 are relatively reduced in height orthickness, and thus the total height or thickness of the package isreduced.

The upper surface of the thickness-reduced center hollow portion 63, onwhich the semiconductor chip 18 is mounted, is lower in level than thetop of the ridged peripheral portion 65 of the resin substrate 62. Thisstructural feature may advantageously prevent an undesirable entry offlux into the cavity 24. Namely, the ridged peripheral portion 65 servesas a barrier wall to flux which surrounds the thickness-reduced centerhollow portion 63, on which the semiconductor chip 18 is mounted. Theflux barrier wall of the ridged peripheral portion 65 is effective toprevent the entry of flux into the cavity 24. This may cause no failureto the electrical characteristic and performance of the packagedsemiconductor device.

Further, the cap bonding face 68 is narrower in width than the substratebonding face 66. Namely, the outside periphery of the cap bonding face68 extends inside the outside periphery of the substrate bonding face66, whilst the inside periphery of the cap bonding face 68 extendsoutside the inside periphery of the substrate bonding face 66. Thisstructural feature enhances the self-alignment function. If the cap 64is placed with miss-alignment over the resin substrate 62, then the widesubstrate bonding face 66 receives the cap bonding face 68, and allowsthe cap 64 to be self-aligned to the resin substrate 62.

The above structural feature may also advantageously allow an effectivereduction in thickness of the thickness-reduced center hollow portion 63so that a distance between upper and bottom surfaces of thethickness-reduced center hollow portion 63 is reduced, thereby allowinga reduction in the length of the leads 14 which extends from the uppersurface of the thickness-reduced center hollow portion 63 to the bottomperiphery of the resin substrate 62. The reduction in length of theleads 14 decreases the inductance thereof. The decrease in theinductance of the leads 14 makes it easy to suppress the undesirablehigh frequency loss of the high frequency semiconductor device.

The above structural feature may further provide an effective reductionin height of the cap 64 with ensuring the sufficient space of the cavity24 which accommodates the semiconductor chip 18. This allows aneffective reduction in the total height of the package.

Further, the cap bonding face 68 and the substrate bonding face 66 areengaged tightly with each other, and each of the cap bonding face 68,and the substrate bonding face 66 comprises the sloped face or thenon-horizontal face, which causes a self-alignment function forself-aligning the cap 64 to the resin substrate 62 due to a self-weightof the cap 64. This self-alignment function allows a desirable automaticassembling process by using an automatic assembling machine without anyexcess high handing-accuracy. The above self-alignment function makesnon-defective the external dimension of the package 60. Thenon-defective external dimension of the package 60 makes the metalwirings free from any undesirable disconnection. The aboveself-alignment function also allows the mass production and improves theyield of the final product.

In addition, the substrate bonding face 66 has an inside extendingregion which further extends in the inward and upward direction from theinside periphery of the cap bonding face 68. The outwardly sloped-downplanes provides the maximum height of the flux barrier wall at theinside thereof. The inside extending region of the substrate bondingface 66 makes it difficult that a part of the flux crimes up in theinward direction along the inside extending region, assuming that thepart of the flux passes through the interface between the substratebonding face 66 and the cap bonding face 68 due to capillary phenomenon.This ensures to prevent the flux from entering into the cavity.

Fourth Embodiment

A fourth embodiment according to the present invention will be describedin detail with reference to the drawings. FIG. 5 is a cross sectionalelevation view illustrative of an internal structure of a novel packagewith a cavity structure in a fourth embodiment in accordance with thepresent invention. The package of this fourth embodiment is differentfrom the package of the first embodiment in the substrate and capbonding faces.

A package 70 with a cavity structure includes a resin substrate 72, asemiconductor chip 18, and a cap 74. The resin substrate 72 furtherincludes a die pad 12 and a set of four leads 14. The resin substrate 72comprises a thickness-reduced center hollow portion 73 and a ridgedperipheral portion 75. The ridged peripheral portion 75 extendsannularly surrounding the periphery of the thickness-reduced centerhollow portion 73. An upper surface of the thickness-reduced centerhollow portion 73 is lower in level than the top of the ridgedperipheral portion 75. The ridged peripheral portion 75 serves as abarrier wall to flux for keeping the thickness-reduced center hollowportion 73 from the flux.

The ridged peripheral portion 75 extends annularly surrounding theperiphery of the thickness-reduced center hollow portion 73. The ridgedperipheral portion 75 includes an inside wall, an outside wall oppositeto the inside wall as well as a rounded groove. The rounded groove isbounded between the inside and outside walls. The rounded groove extendsoutside the inside wall and inside the outside wall. The rounded groovehas a circular band shape in the plan view. The rounded groove has anarched-shape in cross sectional view. In the geometrical viewpoint, thethree dimensional shape of the rounded groove corresponds to a bottomhalf of a torus. The rounded groove provides a substrate bonding face 76for bonding with the cap 74.

The cap 74 is bonded or adhered to the substrate bonding face 76comprising the rounded groove of the ridged peripheral portion 75 of theresin substrate 72, whereby in co-operation with the resin substrate 72,the cap 74 defines a cavity 24 which accommodates the semiconductor chip18. The cavity also contributes to reduce the parasitic capacitance. Thecap 74 comprises a disk-shaped body 77 and a ridged peripheral portion79 which extends annularly surrounding a periphery of the disk-shapedbody 77. The disk-shaped body 77 is generally flat and relatively thin.The ridged peripheral portion 79 is ridged downwardly and toward theresin substrate 72.

The ridged peripheral portion 79 includes an inside wall, an outsidewall opposite to the inside wall as well as a rounded ridge, providedthat the cap 74 is bonded to the resin substrate 72 and the inner wallis faced down. The rounded ridge is bounded between the inside andoutside walls. The rounded ridge extends outside the inside wall andinside the outside wall. The rounded ridge has a circular band shape inthe bottom view. In the geometrical viewpoint, the three dimensionalshape of the inwardly sloped-down face corresponds to a bottom half of atorus.

The rounded ridge of the cap 74 provides a cap bonding face 78 which isadjusted with and engaged with the substrate bonding face 76 of theresin substrate 72. The cap bonding face 78 has a curvature which issubstantially identical with a center region of the above substratebonding face 76, so that the cap bonding face 78 is tightly contact andengaged with the substrate bonding face 76.

As well illustrated, the cap bonding face 78 is narrower in width thanthe substrate bonding face 76. The substrate bonding face 76 has aninside extending region which further extends in the inward and upwarddirection from the inside periphery of the cap bonding face 78. Theinside extending region of the substrate bonding face 76 makes itdifficult that a part of the flux crimes up in the inward directionalong the inside extending region, assuming that the part of the fluxpasses through the interface between the substrate bonding face 76 andthe cap bonding face 78 due to capillary phenomenon. This ensures toprevent the flux from entering into the cavity.

The above package 70 provides the following advantages.

The thickness-reduced center hollow portion 73 contributes to form thecavity 24 which accommodates the semiconductor chip 18, whilst the resinsubstrate 72 and the cap 74 are relatively reduced in height orthickness, and thus the total height or thickness of the package isreduced.

The upper surface of the thickness-reduced center hollow portion 73, onwhich the semiconductor chip 18 is mounted, is lower in level than thetop of the ridged peripheral portion 75 of the resin substrate 72. Thisstructural feature may advantageously prevent an undesirable entry offlux into the cavity 24. Namely, the ridged peripheral portion 75 servesas a barrier wall to flux which surrounds the thickness-reduced centerhollow portion 73, on which the semiconductor chip 18 is mounted. Theflux barrier wall of the ridged peripheral portion 75 is effective toprevent the entry of flux into the cavity 24. This may cause no failureto the electrical characteristic and performance of the packagedsemiconductor device.

Further, the rounded groove of the substrate bonding face 76 may trap orcapture the flux and an excess part of the used adhesive agent toprevent the flux and the excess part of the used adhesive agent fromentering into the cavity 24 and from being adhered onto thesemiconductor chip 18.

The above structural feature may also advantageously allow an effectivereduction in thickness of the thickness-reduced center hollow portion 73so that a distance between upper and bottom surfaces of thethickness-reduced center hollow portion 73 is reduced, thereby allowinga reduction in the length of the leads 14 which extends from the uppersurface of the thickness-reduced center hollow portion 73 to the bottomperiphery of the resin substrate 72. The reduction in length of theleads 14 decreases the inductance thereof. The decrease in theinductance of the leads 14 makes it easy to suppress the undesirablehigh frequency loss of the high frequency semiconductor device.

The above structural feature may further provide an effective reductionin height of the cap 74 with ensuring the sufficient space of the cavity24 which accommodates the semiconductor chip 18. This allows aneffective reduction in the total height of the package.

Further, the cap bonding face 78 and the substrate bonding face 76 areengaged tightly with each other, and the cap bonding face 78, and thesubstrate bonding face 76 comprise the rounded ridge and the roundedgroove, which causes a self-alignment function for self-aligning the cap74 to the resin substrate 72 due to a self-weight of the cap 74. Thisself-alignment function allows a desirable automatic assembling processby using an automatic assembling machine without any excess highhanding-accuracy. The above self-alignment function makes non-defectivethe external dimension of the package 70. The non-defective externaldimension of the package 70 makes the metal wirings free from anyundesirable disconnection. The above self-alignment function also allowsthe mass production and improves the yield of the final product.

In addition, the cap bonding face 78 is narrower in width than thesubstrate bonding face 76. The substrate bonding face 76 has an insideextending region which further extends in the inward and upwarddirection from the inside periphery of the cap bonding face 78. Theinside extending region of the substrate bonding face 76 makes itdifficult that a part of the flux crimes up in the inward directionalong the inside extending region, assuming that the part of the fluxpasses through the interface between the substrate bonding face 76 andthe cap bonding face 78 due to capillary phenomenon. This ensures toprevent the flux from entering into the cavity.

Fifth Embodiment

A fifth embodiment according to the present invention will be describedin detail with reference to the drawings. FIG. 6 is a cross sectionalelevation view illustrative of an internal structure of a novel packagewith a cavity structure in a fifth embodiment in accordance with thepresent invention. The package of this fifth embodiment is differentfrom the package of the first embodiment in the substrate and capbonding faces.

A package 80 with a cavity structure includes a resin substrate 82, asemiconductor chip 18, and a cap 84. The resin substrate 82 furtherincludes a die pad 12 and a set of four leads 14. The resin substrate 82comprises a thickness-reduced center hollow portion 83 and a ridgedperipheral portion 85. The ridged peripheral portion 85 extendsannularly surrounding the periphery of the thickness-reduced centerhollow portion 83. An upper surface of the thickness-reduced centerhollow portion 83 is lower in level than the top of the ridgedperipheral portion 85. The ridged peripheral portion 85 serves as abarrier wall to flux for keeping the thickness-reduced center hollowportion 83 from the flux.

The ridged peripheral portion 85 extends annularly surrounding theperiphery of the thickness-reduced center hollow portion 83. The ridgedperipheral portion 85 includes an inside wall, an outside wall oppositeto the inside wall as well as a V-shaped groove. The V-shaped groove isbounded between the inside and outside walls. The V-shaped grooveextends outside the inside wall and inside the outside wall. TheV-shaped groove has a circular band shape in the plan view. The V-shapedgroove has a V-shaped in cross sectional view. The V-shaped grooveprovides a substrate bonding face 86 for bonding with the cap 84.

The cap 84 is bonded or adhered to the substrate bonding face 86comprising the V-shaped groove of the ridged peripheral portion 85 ofthe resin substrate 82, whereby in co-operation with the resin substrate82, the cap 84 defines a cavity 24 which accommodates the semiconductorchip 18. The cavity also contributes to reduce the parasiticcapacitance. The cap 84 comprises a disk-shaped body 87 and a ridgedperipheral portion 89 which extends annularly surrounding a periphery ofthe disk-shaped body 87. The disk-shaped body 87 is generally flat andrelatively thin. The ridged peripheral portion 89 is ridged downwardlyand toward the resin substrate 82.

The ridged peripheral portion 89 includes an inside wall, an outsidewall opposite to the inside wall as well as a V-shaped ridge, providedthat the cap 84 is bonded to the resin substrate 82 and the inner wallis faced down. The V-shaped ridge is bounded between the inside andoutside walls. The V-shaped ridge extends outside the inside wall andinside the outside wall. The V-shaped ridge has a circular band shape inthe bottom view.

The V-shaped ridge of the cap 84 provides a cap bonding face 88 which isadjusted with and engaged with the substrate bonding face 86 of theresin substrate 82. The cap bonding face 88 has an included angle whichis substantially identical with the included angle of the abovesubstrate bonding face 86, so that the cap bonding face 88 is tightlycontact and engaged with the substrate bonding face 86.

As well illustrated, the cap bonding face 88 is narrower in width thanthe substrate bonding face 86. The substrate bonding face 86 has aninside extending region which further extends in the inward and upwarddirection from the inside periphery of the cap bonding face 88. Theinside extending region of the substrate bonding face 86 makes itdifficult that a part of the flux crimes up in the inward directionalong the inside extending region, assuming that the part of the fluxpasses through the interface between the substrate bonding face 86 andthe cap bonding face 88 due to capillary phenomenon. This ensures toprevent the flux from entering into the cavity.

The above package 80 provides the following advantages.

The thickness-reduced center hollow portion 83 contributes to form thecavity 24 which accommodates the semiconductor chip 18, whilst the resinsubstrate 82 and the cap 84 are relatively reduced in height orthickness, and thus the total height or thickness of the package isreduced.

The upper surface of the thickness-reduced center hollow portion 83, onwhich the semiconductor chip 18 is mounted, is lower in level than thetop of the ridged peripheral portion 85 of the resin substrate 82. Thisstructural feature may advantageously prevent an undesirable entry offlux into the cavity 24. Namely, the ridged peripheral portion 85 servesas a barrier wall to flux which surrounds the thickness-reduced centerhollow portion 83, on which the semiconductor chip 18 is mounted. Theflux barrier wall of the ridged peripheral portion 85 is effective toprevent the entry of flux into the cavity 24. This may cause no failureto the electrical characteristic and performance of the packagedsemiconductor device.

Further, the V-shaped groove of the substrate bonding face 86 may trapor capture the flux and an excess part of the used adhesive agent toprevent the flux and the excess part of the used adhesive agent fromentering into the cavity 24 and from being adhered onto thesemiconductor chip 18.

The above structural feature may also advantageously allow an effectivereduction in thickness of the thickness-reduced center hollow portion 83so that a distance between upper and bottom surfaces of thethickness-reduced center hollow portion 83 is reduced, thereby allowinga reduction in the length of the leads 14 which extends from the uppersurface of the thickness-reduced center hollow portion 83 to the bottomperiphery of the resin substrate 82. The reduction in length of theleads 14 decreases the inductance thereof. The decrease in theinductance of the leads 14 makes it easy to suppress the undesirablehigh frequency loss of the high frequency semiconductor device.

The above structural feature may further provide an effective reductionin height of the cap 84 with ensuring the sufficient space of the cavity24 which accommodates the semiconductor chip 18. This allows aneffective reduction in the total height of the package.

Further, the cap bonding face 88 and the substrate bonding face 86 areengaged tightly with each other, and the cap bonding face 88, and thesubstrate bonding face 86 comprise the V-shaped ridge and the V-shapedgroove, which causes a self-alignment function for self-aligning the cap84 to the resin substrate 82 due to a self-weight of the cap 84. Thisself-alignment function allows a desirable automatic assembling processby using an automatic assembling machine without any excess highhanding-accuracy. The above self-alignment function makes non-defectivethe external dimension of the package 80. The non-defective externaldimension of the package 80 makes the metal wirings free from anyundesirable disconnection. The above self-alignment function also allowsthe mass production and improves the yield of the final product.

In addition, the cap bonding face 88 is narrower in width than thesubstrate bonding face 86. The substrate bonding face 86 has an insideextending region which further extends in the inward and upwarddirection from the inside periphery of the cap bonding face 88. Theinside extending region of the substrate bonding face 86 makes itdifficult that a part of the flux crimes up in the inward directionalong the inside extending region, assuming that the part of the fluxpasses through the interface between the substrate bonding face 86 andthe cap bonding face 88 due to capillary phenomenon. This ensures toprevent the flux from entering into the cavity.

Sixth Embodiment

A sixth embodiment according to the present invention will be describedin detail with reference to the drawings. FIG. 7 is a cross sectionalelevation view illustrative of an internal structure of a novel packagewith a cavity structure in a sixth embodiment in accordance with thepresent invention. The package of this sixth embodiment is differentfrom the package of the first embodiment in the substrate and capbonding faces.

A package 90 with a cavity structure includes a resin substrate 92, asemiconductor chip 18, and a cap 94. The resin substrate 92 furtherincludes a die pad 12 and a set of four leads 14. The resin substrate 92comprises a thickness-reduced center hollow portion 93 and a ridgedperipheral portion 95. The ridged peripheral portion 95 extendsannularly surrounding the periphery of the thickness-reduced centerhollow portion 93. An upper surface of the thickness-reduced centerhollow portion 93 is lower in level than the top of the ridgedperipheral portion 95. The ridged peripheral portion 95 serves as abarrier wall to flux for keeping the thickness-reduced center hollowportion 93 from the flux.

The ridged peripheral portion 95 extends annularly surrounding theperiphery of the thickness-reduced center hollow portion 93. The ridgedperipheral portion 95 includes an inside wall, an outside wall oppositeto the inside wall as well as a trapezoid-shaped groove. Thetrapezoid-shaped groove is bounded between the inside and outside walls.The trapezoid-shaped groove extends outside the inside wall and insidethe outside wall. The trapezoid-shaped groove has a circular band shapein the plan view. The trapezoid-shaped groove has a trapezoid-shape incross sectional view. The trapezoid-shaped groove provides a substratebonding face 96 for bonding with the cap 94.

The trapezoid-shaped groove as the substrate bonding face 96 furthercomprises an inwardly sloped down face, a flat bottom face and anoutwardly sloped down face. The inwardly sloped down face is boundedbetween the outside wall and the flat bottom face. The inwardly slopeddown face extends outside the flat bottom face and inside the outsidewall. The inwardly sloped down face has an uniform slope angle. The flatbottom face is bounded between the inwardly sloped down face and theoutwardly sloped down face. The flat bottom face extends outside theoutwardly sloped down face and inside the inwardly sloped down face. Theflat bottom face has a horizontal face. The outwardly sloped down faceis bounded between the inside wall and the flat bottom face. Theoutwardly sloped down face extends inside the flat bottom face andoutside the inside wall. The outwardly sloped down face has an uniformslope angle. The inwardly sloped down face provides a first substratebonding face 96 a. The flat bottom face provides a second substratebonding face 96 b. The outwardly sloped down face provides a thirdsubstrate bonding face 96 c. The above substrate bonding face 96 furthercomprises the first to third substrate bonding faces 96 a, 96 b and 96c.

The cap 94 is bonded or adhered to the substrate bonding face 96comprising the trapezoid-shaped groove of the ridged peripheral portion95 of the resin substrate 92, whereby in co-operation with the resinsubstrate 92, the cap 94 defines a cavity 24 which accommodates thesemiconductor chip 18. The cavity also contributes to reduce theparasitic capacitance. The cap 94 comprises a disk-shaped body 97 and aridged peripheral portion 99 which extends annularly surrounding aperiphery of the disk-shaped body 97. The disk-shaped body 97 isgenerally flat and relatively thin. The ridged peripheral portion 99 isridged downwardly and toward the resin substrate 92.

The ridged peripheral portion 99 includes an inside wall, an outsidewall opposite to the inside wall as well as a trapezoid-shaped ridge,provided that the cap 94 is bonded to the resin substrate 92 and theinner wall is faced down. The trapezoid-shaped ridge is bounded betweenthe inside and outside walls. The trapezoid-shaped ridge extends outsidethe inside wall and inside the outside wall. The trapezoid-shaped ridgehas a circular band shape in the bottom view.

The trapezoid-shaped ridge of the cap 94 provides a cap bonding face 98which is adjusted with and engaged with the substrate bonding face 96 ofthe resin substrate 92. The cap bonding face 98 has a sectioned shapewhich is substantially identical with the above substrate bonding face96, so that the cap bonding face 98 is tightly contact and engaged withthe substrate bonding face 96.

The trapezoid-shaped ridge as the cap bonding face 98 further comprisesan inwardly sloped down face, a flat top face and an outwardly slopeddown face. The inwardly sloped down face is bounded between the outsidewall and the flat top face. The inwardly sloped down face extendsoutside the flat top face and inside the outside wall. The inwardlysloped down face has an uniform slope angle which is identical with theinwardly sloped down face of the trapezoid-shaped groove 96. The flattop face is bounded between the inwardly sloped down face and theoutwardly sloped down face. The flat top face extends outside theoutwardly sloped down face and inside the inwardly sloped down face. Theflat top face has a horizontal face. The outwardly sloped down face isbounded between the inside wall and the flat top face. The outwardlysloped down face extends inside the flat top face and outside the insidewall. The outwardly sloped down face has an uniform slope angle which isidentical with the outwardly sloped down face of the trapezoid-shapedgroove 98. The inwardly sloped down face provides a first cap bondingface 98 a. The flat bottom face provides a second cap bonding face 98 b.The outwardly sloped down face provides a third cap bonding face 98 c.The above cap bonding face 98 further comprises the first to third capbonding faces 98 a, 98 b and 98 c. The first cap bonding face 98 a isengaged with the first substrate bonding face 96 a. The second capbonding face 98 b is engaged with the second substrate bonding face 96b. The third cap bonding face 98 c is engaged with the third substratebonding face 96 c.

As well illustrated, the cap bonding face 98 is narrower in width thanthe substrate bonding face 96. The substrate bonding face 96 has aninside extending region which further extends in the inward and upwarddirection from the inside periphery of the cap bonding face 98. Theinside extending region of the substrate bonding face 96 makes itdifficult that a part of the flux crimes up in the inward directionalong the inside extending region, assuming that the part of the fluxpasses through the interface between the substrate bonding face 96 andthe cap bonding face 98 due to capillary phenomenon. This ensures toprevent the flux from entering into the cavity.

The above package 90 provides the following advantages.

The thickness-reduced center hollow portion 93 contributes to form thecavity 24 which accommodates the semiconductor chip 18, whilst the resinsubstrate 92 and the cap 94 are relatively reduced in height orthickness, and thus the total height or thickness of the package isreduced.

The upper surface of the thickness-reduced center hollow portion 93, onwhich the semiconductor chip 18 is mounted, is lower in level than thetop of the ridged peripheral portion 95 of the resin substrate 92. Thisstructural feature may advantageously prevent an undesirable entry offlux into the cavity 24. Namely, the ridged peripheral portion 95 servesas a barrier wall to flux which surrounds the thickness-reduced centerhollow portion 93, on which the semiconductor chip 18 is mounted. Theflux barrier wall of the ridged peripheral portion 95 is effective toprevent the entry of flux into the cavity 24. This may cause no failureto the electrical characteristic and performance of the packagedsemiconductor device.

Further, the trapezoid-shaped groove of the substrate bonding face 96may trap or capture the flux and an excess part of the used adhesiveagent to prevent the flux and the excess part of the used adhesive agentfrom entering into the cavity 24 and from being adhered onto thesemiconductor chip 18.

The above structural feature may also advantageously allow an effectivereduction in thickness of the thickness-reduced center hollow portion 93so that a distance between upper and bottom surfaces of thethickness-reduced center hollow portion 93 is reduced, thereby allowinga reduction in the length of the leads 14 which extends from the uppersurface of the thickness-reduced center hollow portion 93 to the bottomperiphery of the resin substrate 92. The reduction in length of theleads 14 decreases the inductance thereof. The decrease in theinductance of the leads 14 makes it easy to suppress the undesirablehigh frequency loss of the high frequency semiconductor device.

The above structural feature may further provide an effective reductionin height of the cap 94 with ensuring the sufficient space of the cavity24 which accommodates the semiconductor chip 18. This allows aneffective reduction in the total height of the package.

Further, the cap bonding face 98 and the substrate bonding face 96 areengaged tightly with each other, and the cap bonding face 98, and thesubstrate bonding face 96 comprise the trapezoid-shaped ridge and thetrapezoid-shaped groove, which causes a self-alignment function forself-aligning the cap 94 to the resin substrate 92 due to a self-weightof the cap 94. This self-alignment function allows a desirable automaticassembling process by using an automatic assembling machine without anyexcess high handing-accuracy. The above self-alignment function makesnon-defective the external dimension of the package 90. Thenon-defective external dimension of the package 90 makes the metalwirings free from any undesirable disconnection. The aboveself-alignment function also allows the mass production and improves theyield of the final product.

In addition, the cap bonding face 98 is narrower in width than thesubstrate bonding face 96. The substrate bonding face 96 has an insideextending region which further extends in the inward and upwarddirection from the inside periphery of the cap bonding face 98. Theinside extending region of the substrate bonding face 96 makes itdifficult that a part of the flux crimes up in the inward directionalong the inside extending region, assuming that the part of the fluxpasses through the interface between the substrate bonding face 96 andthe cap bonding face 98 due to capillary phenomenon. This ensures toprevent the flux from entering into the cavity.

Moreover, the combination of the second substrate bonding face 96 b andthe second cap bonding face 98 b makes it easy to apply an adhesiveagent onto at least one of the second substrate bonding face 96 b andthe second cap bonding face 98 b for bonding the cap 94 to the resinsubstrate 92. This may contribute to improve the productivity of thepackage 90.

Seventh Embodiment

A seventh embodiment according to the present invention will bedescribed in detail with reference to the drawings. FIG. 8 is a crosssectional elevation view illustrative of an internal structure of anovel package with a cavity structure in a seventh embodiment inaccordance with the present invention. The package of this seventhembodiment is different from the package of the first embodiment in thesubstrate and cap bonding faces.

A package 100 with a cavity structure includes a resin substrate 102, asemiconductor chip 18, and a cap 104. The resin substrate 102 furtherincludes a die pad 12 and a set of four leads 14. The resin substrate102 comprises a thickness-reduced center hollow portion 103 and a ridgedperipheral portion 105. The ridged peripheral portion 105 extendsannularly surrounding the periphery of the thickness-reduced centerhollow portion 103. An upper surface of the thickness-reduced centerhollow portion 103 is lower in level than the top of the ridgedperipheral portion 105. The ridged peripheral portion 105 serves as abarrier wall to flux for keeping the thickness-reduced center hollowportion 103 from the flux.

The ridged peripheral portion 105 extends annularly surrounding theperiphery of the thickness-reduced center hollow portion 103. The ridgedperipheral portion 105 includes an inside wall, an outside wall oppositeto the inside wall as well as a rounded ridge. The rounded ridge isbounded between the inside and outside walls. The rounded ridge extendsoutside the inside wall and inside the outside wall. The rounded ridgehas a circular band shape in the plan view. The rounded ridge has anarched-shape in cross sectional view. The rounded ridge provides asubstrate bonding face 106 for bonding with the cap 104.

The cap 104 is bonded or adhered to the substrate bonding face 106comprising the rounded ridge of the ridged peripheral portion 105 of theresin substrate 102, whereby in co-operation with the resin substrate102, the cap 104 defines a cavity 24 which accommodates thesemiconductor chip 18. The cavity also contributes to reduce theparasitic capacitance. The cap 104 comprises a disk-shaped body 107 anda ridged peripheral portion 109 which extends annularly surrounding aperiphery of the disk-shaped body 107. The disk-shaped body 107 isgenerally flat and relatively thin. The ridged peripheral portion 109 isridged downwardly and toward the resin substrate 102.

The ridged peripheral portion 109 includes an inside wall, an outsidewall opposite to the inside wall as well as a rounded groove, providedthat the cap 104 is bonded to the resin substrate 102 and the inner wallis faced down. The rounded groove is bounded between the inside andoutside walls. The rounded groove extends outside the inside wall andinside the outside wall. The rounded groove has a circular band shape inthe bottom view.

The rounded groove of the cap 104 provides a cap bonding face 108 whichis adjusted with and engaged with the substrate bonding face 106 of theresin substrate 102. The cap bonding face 108 has a curvature which issubstantially identical with a center region of the above substratebonding face 106, so that the cap bonding face 108 is tightly contactand engaged with the substrate bonding face 106. As well illustrated,the cap bonding face 108 is narrower in width than the substrate bondingface 106. The substrate bonding face 106 has an inside extending regionwhich further extends in the inward and downward direction from theinside periphery of the cap bonding face 108.

The above package 100 provides the following advantages.

The thickness-reduced center hollow portion 103 contributes to form thecavity 24 which accommodates the semiconductor chip 18, whilst the resinsubstrate 102 and the cap 104 are relatively reduced in height orthickness, and thus the total height or thickness of the package isreduced.

The upper surface of the thickness-reduced center hollow portion 103, onwhich the semiconductor chip 18 is mounted, is lower in level than thetop of the ridged peripheral portion 105 of the resin substrate 102.This structural feature may advantageously prevent an undesirable entryof flux into the cavity 24. Namely, the ridged peripheral portion 105serves as a barrier wall to flux which surrounds the thickness-reducedcenter hollow portion 103, on which the semiconductor chip 18 ismounted. The flux barrier wall of the ridged peripheral portion 105 iseffective to prevent the entry of flux into the cavity 24. This maycause no failure to the electrical characteristic and performance of thepackaged semiconductor device.

The above structural feature may also advantageously allow an effectivereduction in thickness of the thickness-reduced center hollow portion103 so that a distance between upper and bottom surfaces of thethickness-reduced center hollow portion 103 is reduced, thereby allowinga reduction in the length of the leads 14 which extends from the uppersurface of the thickness-reduced center hollow portion 103 to the bottomperiphery of the resin substrate 102. The reduction in length of theleads 14 decreases the inductance thereof. The decrease in theinductance of the leads 14 makes it easy to suppress the undesirablehigh frequency loss of the high frequency semiconductor device.

The above structural feature may further provide an effective reductionin height of the cap 104 with ensuring the sufficient space of thecavity 24 which accommodates the semiconductor chip 18. This allows aneffective reduction in the total height of the package.

Further, the cap bonding face 108 and the substrate bonding face 106 areengaged tightly with each other, and the cap bonding face 108, and thesubstrate bonding face 106 comprise the rounded groove and the roundedridge, which causes a self-alignment function for self-aligning the cap104 to the resin substrate 102 due to a self-weight of the cap 104. Thisself-alignment function allows a desirable automatic assembling processby using an automatic assembling machine without any excess highhanding-accuracy. The above self-alignment function makes non-defectivethe external dimension of the package 100. The non-defective externaldimension of the package 100 makes the metal wirings free from anyundesirable disconnection. The above self-alignment function also allowsthe mass production and improves the yield of the final product.

Eighth Embodiment

An eighth embodiment according to the present invention will bedescribed in detail with reference to the drawings. FIG. 9 is a crosssectional elevation view illustrative of an internal structure of anovel package with a cavity structure in an eighth embodiment inaccordance with the present invention. The package of this eighthembodiment is different from the package of the first embodiment in thesubstrate and cap bonding faces.

A package 110 with a cavity structure includes a resin substrate 112, asemiconductor chip 18, and a cap 114. The resin substrate 112 furtherincludes a die pad 12 and a set of four leads 14. The resin substrate112 comprises a thickness-reduced center hollow portion 113 and a ridgedperipheral portion 115. The ridged peripheral portion 115 extendsannularly surrounding the periphery of the thickness-reduced centerhollow portion 113. An upper surface of the thickness-reduced centerhollow portion 113 is lower in level than the top of the ridgedperipheral portion 115. The ridged peripheral portion 115 serves as abarrier wall to flux for keeping the thickness-reduced center hollowportion 113 from the flux.

The ridged peripheral portion 115 extends annularly surrounding theperiphery of the thickness-reduced center hollow portion 113. The ridgedperipheral portion 115 includes an inside wall, an outside wall oppositeto the inside wall as well as a V-shaped ridge. The V-shaped ridge isbounded between the inside and outside walls. The V-shaped ridge extendsoutside the inside wall and inside the outside wall. The V-shaped ridgehas a circular band shape in the plan view. The V-shaped ridge has aV-shape in cross sectional view. The V-shaped ridge provides a substratebonding face 116 for bonding with the cap 114.

The cap 114 is bonded or adhered to the substrate bonding face 116comprising the V-shaped ridge of the ridged peripheral portion 115 ofthe resin substrate 112, whereby in co-operation with the resinsubstrate 112, the cap 114 defines a cavity 24 which accommodates thesemiconductor chip 18. The cavity also contributes to reduce theparasitic capacitance. The cap 114 comprises a disk-shaped body 117 anda ridged peripheral portion 119 which extends annularly surrounding aperiphery of the disk-shaped body 117. The disk-shaped body 117 isgenerally flat and relatively thin. The ridged peripheral portion 119 isridged downwardly and toward the resin substrate 112.

The ridged peripheral portion 119 includes an inside wall, an outsidewall opposite to the inside wall as well as a V-shaped groove, providedthat the cap 114 is bonded to the resin substrate 112 and the inner wallis faced down. The V-shaped groove is bounded between the inside andoutside walls. The V-shaped groove extends outside the inside wall andinside the outside wall. The V-shaped groove has a circular band shapein the bottom view.

The V-shaped groove of the cap 114 provides a cap bonding face 118 whichis adjusted with and engaged with the substrate bonding face 116 of theresin substrate 112. The cap bonding face 118 has an included anglewhich is substantially identical with a center region of the abovesubstrate bonding face 116, so that the cap bonding face 118 is tightlycontact and engaged with the substrate bonding face 116. As wellillustrated, the cap bonding face 118 is narrower in width than thesubstrate bonding face 116. The substrate bonding face 116 has an insideextending region which further extends in the inward and downwarddirection from the inside periphery of the cap bonding face 118.

The above package 110 provides the following advantages.

The thickness-reduced center hollow portion 113 contributes to form thecavity 24 which accommodates the semiconductor chip 18, whilst the resinsubstrate 112 and the cap 114 are relatively reduced in height orthickness, and thus the total height or thickness of the package isreduced.

The upper surface of the thickness-reduced center hollow portion 113, onwhich the semiconductor chip 18 is mounted, is lower in level than thetop of the ridged peripheral portion 115 of the resin substrate 112.This structural feature may advantageously prevent an undesirable entryof flux into the cavity 24. Namely, the ridged peripheral portion 115serves as a barrier wall to flux which surrounds the thickness-reducedcenter hollow portion 113, on which the semiconductor chip 18 ismounted. The flux barrier wall of the ridged peripheral portion 115 iseffective to prevent the entry of flux into the cavity 24. This maycause no failure to the electrical characteristic and performance of thepackaged semiconductor device.

The above structural feature may also advantageously allow an effectivereduction in thickness of the thickness-reduced center hollow portion113 so that a distance between upper and bottom surfaces of thethickness-reduced center hollow portion 113 is reduced, thereby allowinga reduction in the length of the leads 14 which extends from the uppersurface of the thickness-reduced center hollow portion 113 to the bottomperiphery of the resin substrate 112. The reduction in length of theleads 14 decreases the inductance thereof. The decrease in theinductance of the leads 14 makes it easy to suppress the undesirablehigh frequency loss of the high frequency semiconductor device.

The above structural feature may further provide an effective reductionin height of the cap 114 with ensuring the sufficient space of thecavity 24 which accommodates the semiconductor chip 18. This allows aneffective reduction in the total height of the package.

Further, the cap bonding face 118 and the substrate bonding face 116 areengaged tightly with each other, and the cap bonding face 118, and thesubstrate bonding face 116 comprise the V-shaped groove and the V-shapedridge, which causes a self-alignment function for self-aligning the cap114 to the resin substrate 112 due to a self-weight of the cap 114. Thisself-alignment function allows a desirable automatic assembling processby using an automatic assembling machine without any excess highhanding-accuracy. The above self-alignment function makes non-defectivethe external dimension of the package 110. The non-defective externaldimension of the package 110 makes the metal wirings free from anyundesirable disconnection. The above self-alignment function also allowsthe mass production and improves the yield of the final product.

Although the invention has been described above in connection withseveral preferred embodiments therefor, it will be appreciated thatthose embodiments have been provided solely for illustrating theinvention, and not in a limiting sense. Numerous modifications andsubstitutions of equivalent materials and techniques will be readilyapparent to those skilled in the art after reading the presentapplication, and all such modifications and substitutions are expresslyunderstood to fall within the true scope and spirit of the appendedclaims.

1. A semiconductor package comprising: a substrate having a sidewall,said sidewall surrounding a central portion of said substrate; asemiconductor chip mounted on said substrate; and a cap bonded to anupper surface of said side wall, wherein all bonding surfaces betweenthe sidewall and the cap are sloped to one direction.
 2. Thesemiconductor package according to claim 1, further comprising aplurality of leads electrically coupled to said semiconductor chip, eachof said plurality of leads penetrating said substrate and extending outof said substrate.
 3. The semiconductor package according to claim 1,wherein said cap defines a cavity space, which accommodates saidsemiconductor chip.
 4. The semiconductor package as claimed in claim 1,wherein said substrate has a substrate bonding face and said cap has acap bonding face, each of said cap bonding face and said substratebonding face comprises an inwardly sloped-down plane surface whichextends annularly.
 5. The semiconductor package as claimed in claim 1,wherein said substrate has a substrate bonding face and said cap has acap bonding face, each of said cap bonding face and said substratebonding face comprises an outwardly sloped down plane surface whichextends annularly.
 6. The semiconductor package as claimed in claim 1,wherein said cap has a cap bonding face, said cap comprising a flat bodyand a peripheral portion which has said cap bonding face.
 7. Thesemiconductor package as claimed in claim 1, wherein said plurality ofleads are four in number and each of said four leads extends radiallyand outwardly from said substrate, so that each lead is spacedsubstantially 90° from an adjacent one of said four leads.
 8. Thesemiconductor package as claimed in claim 1, wherein said bondingsurfaces are sloped inwardly toward said semiconductor chip.
 9. Thesemiconductor package as claimed in claim 1, wherein said bondingsurfaces are sloped outwardly away from said semiconductor chip.
 10. Asemiconductor package comprising: a substantially cup-shaped substratehaving a central portion and a sidewall surrounding said centralportion; a semiconductor chip mounted on a top surface of said centralportion; and a cap bonded to an upper surface of said side wall, whereinall bonding surfaces between the sidewall and the cap are sloped to onedirection.
 11. The semiconductor package according to claim 10, whereinall said bonding surfaces between the sidewall and the cap compriseinwardly slopeddown surfaces.
 12. The semiconductor package according toclaim 11, wherein said inwardly sloped-down surfaces extend annularly.13. The semiconductor package according to claim 10, wherein all saidbonding surfaces between the sidewall and the cap comprise outwardlysloped-down surfaces.
 14. The semiconductor package according to claim13, wherein said outwardly sloped-down surfaces extend annularly. 15.The semiconductor package according to claim 10, further comprising aplurality of leads electrically coupled to said semiconductor chip, eachof said plurality of leads penetrating said substrate and extending outof said substrate and coplanar with a bottom surface of said centralportion.